Obesity
Conditions
Keywords
obese, overweight, fMRI, Diet
Brief summary
To evaluate whether changes in macronutrient consumption (i.e., switching to a diet low in carbohydrates) can change brain responses to cues depicting foods representing that macronutrient. In addition to answering specific questions regarding the effects of an LCKD, the study will provide general information about relations between brain responses to food cues and a broad arrive of factors including typical diet, food preferences, weight control history and genes.
Detailed description
We propose a parallel arm randomized clinical trial of two diets-a low carbohydrate ketogenic diet (LCKD) and a low fat diet (LFD). Following screening, eligible participants will undergo a six week dietary intervention that will include 7 clinic visits at the Duke Lifestyle Medicine Clinic (Director: Dr. Westman). In addition to the dietary intervention, participants will undergo fMRI scanning on two occasions: once in the week prior to randomization to a diet (Baseline Scan) and after three weeks of following a diet (Post-Diet Scan). During scanning participants will view food cues in order to assess the effects of diet on brain responses to different macronutrient content categories (e.g., High vs. Low Complex Carbohydrate). In addition to scanning measures, we will also record information regarding dietary intake, food preferences, weight, mood, and diet adherence.
Interventions
BEHAVIORALLow Carbohydrate Ketogenic Diet (LCKD)
participants will follow a low carbohydrate ketogenic diet for six weeks
BEHAVIORALLow Fat Diet (LFD)
particpants will follow a low fat diet for six weeks
Sponsors
Robert C. Atkins Foundation
Duke University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 50 Years
Healthy volunteers
Yes
Inclusion criteria
Participants must be 18-50 years old, right handed and have a BMI \> 27 kg/m². They must be willing to follow either of the two diets.
Exclusion criteria
1. weigh over 300lbs. 2. have uncontrolled hypertension (systolic \>160mm Hg, diastolic \>100mm Hg) 3. have hypotension (systolic \<90 mm Hg, diastolic \<60 mm Hg) 4. have coronary heart disease, or cardiac rhythm disorder 5. cerebrovascular disease or peripheral vascular disease that requires intensive hyperlipidemic therapy 6. other significant co-morbid illnesses such as liver disease (AST or ALT \> 100), kidney disease (serum creatinine \> 1.5), cancer, severe emphysema, severe hypertriglyceridemia (TG\>500) 7. have diabetes (insulin or diet controlled) 8. have a current psychiatric disease 9. have current alcohol abuse (greater than 12 drinks per week) 10. have current drug abuse (or treatment within the last year) 11. use of psychiatric medications (including antidepressants, anti-anxiety agents, anti-psychotics, muscle relaxants or any other drug that influences mood, cognition, or neurotransmitter systems, i.e. dopamine, norepinephrine, acetylcholine, serotonin, GABA, and glutamate) 12. have had or have an eating disorder including anorexia nervosa, bulimia nervosa, eating disorder not otherwise specified, binge eating disorder, or any other form of disordered eating 13. have had any bariatric/weight loss surgery 14. be taking any diet pills (prescription or over the counter) 15. have been on any diet in the last 3 months 16. have any restrictive dietary requirements (including: vegetarians, vegans, or any other dietary restraints) 17. have any food allergies 18. be on an exclusively ethnic diet 19. be females who are pregnant, nursing mothers or likely to become pregnant 20. have any major medical condition that would make participation unsafe (e.g., have pacemaker or other metallic implant (including dental, orthopedic, or IUD), uncomfortable (e.g., chronic pain), confound results (e.g., psychiatric condition) 21. be left handed 22. have glaucoma, color blindness 23. be using experimental or investigational drugs 24. or suffering from claustrophobia
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Compared to individuals in the LFD group, individuals placed on an LCKD will exhibit decreased brain responses to high-carbohydrate food cues. | 1 month |
Secondary
| Measure | Time frame |
|---|---|
| In addition to these questions, we will also examine relations between food consumption acquired from the diaries, genetic factors and brain function. | 1 month |
Countries
United States
Outcome results
None listed